I get that when removing the ICE from the car for conversion every car will be different based on how the conversion is going to proceed.

I'm planning on leaving the gearbox and the brakes. So I'll leave the brake booster, master cylinder brake lines etc. It looks like it's easier to use an aftermarket demisting solution so I'll remove the water heater.

But aside from those very obvious things, I'm going to need to remove basically everything from the engine bay right? I pulled out the radiator and go to the washer fluid bottle and paused and thought I should check here before I go further.

Are there any tips or suggestions for the best way to identify what's coming out of the engine bay?

Initially limit what you are pulling out to the engine and stuff attached to it. Eg. Aircon, steering pump etc.
Only remove other stuff if it's in your way. It's surprizing how easy it is to forger where to put stuff back as the months drift by...
I had lots of sandwich bags with correct fasteners in them tied to the thingy that got pulled out.